Test of parietal lobe function and associated methods

ABSTRACT

A method for testing for a parietal lobe function deficiency, an occipital lobe function deficiency, and a developmental language disorder in a subject includes displaying to a subject ordered arrays of objects having features in a plurality of dimensions, which the subject is prompted to name. The named features are compared with the correct object features, and a count is maintained of errors and an interval taken to complete the naming process. These numbers are compared with predetermined data to determine possible deficiencies.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to application Ser. No. 10/245,456, filed Sep. 17, 2002, entitled “Test of Parietal Lobe Function and Associated Methods,” now U.S. Pat. No. 6,884,078.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to tests of mental function and methods of administering same, and, more particularly, to such tests for Alzheimer's disease.

2. Description of Related Art

It is known to use rapid automatic naming tasks for probing for neurological impairments. The “Stroop Color-Word Test” and color-form tests are known for testing for Alzheimer's disease. The Stroop Color and Word Test is known to be a standard measure in neurophysiological assessment for measuring cognitive processing. In this test the test-taker looks at a sheet of color words printed in black ink, a color page with “X”s printed in color, and a color-word page with words from the first page printed in colors from the second page, with the color and word not matching. The test-taker looks at each sheet and moves down the columns, reading words or naming the ink colors as quickly as possible within a time limit. The Stroop test is also available for administration via computer.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a verbally based test of parietal lobe function.

It is a further object to provide such a verbally based test for Alzheimer's disease.

It is another object to provide a method of administering a test of parietal lobe function.

It is an additional object to provide such a method of administering a test for Alzheimer's disease.

These and other objects are achieved by the present invention, a test, system, and method for testing parietal lobe function in a subject. The method comprises the steps of displaying to a subject a first ordered array of objects having a variety of colors. Preferably each object has a unitary shape. The subject is prompted to name the object colors sequentially in order. The named object colors are then compared with the correct object colors, and a count is maintained of errors in the named object colors. Also, an interval taken by the subject to complete naming the object colors is timed.

The color-naming error count and interval are then compared with a predetermined color-naming error count and interval. The maintained color-naming error count and/or the timed interval being greater than the predetermined color-naming error count and interval is indicative of a possible parietal lobe function deficiency.

In another portion of the method, a second ordered array of objects having a variety of shapes is displayed to the subject. The subject is prompted to name the object shapes sequentially in order. The named object shapes are compared with the correct object shapes. A count of errors in the named object shapes is maintained, and an interval taken by the subject to complete naming the object shapes is timed.

The shape-naming error count and interval are then compared with a predetermined shape-naming error count and interval. the maintained shape-naming error count and/or the timed interval being greater than the predetermined shape-naming error count and interval is indicative of a possible parietal lobe function deficiency.

The test, system, and method of the present invention provide a rapid, objective, reliable, and sensitive standardized, neurolinguistic screening tool designed to assess: automaticity, speed, and fluency in naming; the ability to perform rapid cognitive shifts between the visual stimuli that form the input and the semantic fields from which the appropriate names must be retrieved; activation of working memory for processing and monitoring naming of familiar visual stimuli; and parietal lobe functioning associated with neurogenic disorders.

The test of the present invention can be used to screen adolescents and adults for parietal lobe dysfunction indicative of mild cognitive impairments, acquired neurogenic disorders of language and communication (aphasia or TBI, late-onset depression, bipolar disorders, epilepsy), or degenerative neurological disorders such as Alzheimer's or Parkinsonism. It can also be used to screen adolescents or adults with suspected or diagnosed language disorders, learning disabilities (LD), attention deficit/hyperactive disorders (AD/HD), and other syndromes associated with parietal lobe dysfunction. The test is a measure of response speed in which individual differences depend on the speed and accuracy (automaticity) of performance.

Although other continuous naming tasks are known in the art, the present invention is distinguished by the following features:

1 The test is designed to allow for administration and interpretation across linguistic codes and cultural domains.

2. The visual stimuli are familiar across many cultures.

3. The test design enables examiners from other cultural-linguistic communities to develop directions for administration and standards for verbal responses that are representative of their language.

4. Examiners can use the test to conduct comparative evaluations of adolescents and adults with monolingual or bilingual backgrounds.

It will be understood by one of skill in the art that the order presented above is not intended as limiting, and that the order of the two portions of the test administration method may be reversed without departing from the spirit of the invention.

The features that characterize the invention, both as to organization and method of operation, together with further objects and advantages thereof, will be better understood from the following description used in conjunction with the accompanying drawing. It is to be expressly understood that the drawing is for the purpose of illustration and description and is not intended as a definition of the limits of the invention. These and other objects attained, and advantages offered, by the present invention will become more fully apparent as the description that now follows is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-ID is a flow chart of a preferred embodiment of the present invention.

FIG. 1E is a flow chart of an alternate embodiment for part of the method of FIGS. 1A-1D.

FIGS. 2A,2B illustrate exemplary displays for the first and second portion of a practice test, respectively.

FIG. 3 illustrates an exemplary display for the third portion of a practice test.

FIG. 4 illustrates an exemplary display for the first portion of the test.

FIG. 5 illustrates an exemplary display for the second portion of the test.

FIG. 6 illustrates an exemplary display for the third portion of the test.

FIG. 7A illustrates an exemplary Response Form.

FIG. 7B illustrates an exemplary time performance graph.

FIG. 8 is a schematic diagram of a computerized test administration system.

FIG. 9A is a schematic diagram of an automated test administration system.

FIG. 9B is a schematic diagram of an automated test administration system administerable over a network.

FIG. 10 illustrates an exemplary display of a letter array.

FIG. 11 illustrates an exemplary display of an object array.

FIG. 12 illustrates an exemplary display of an animal array.

FIG. 13 illustrates an exemplary display of a household object array.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A description of the preferred embodiments of the present invention will now be presented with reference to FIGS. 1A-13.

The present invention includes a test, system, and method for testing parietal lobe function in a subject, typically administered by an examiner. The method 100, illustrated in flowchart form in FIGS. 1A-1D, includes a practice phase having three portions. The practice phase first portion comprises the steps of displaying to the subject a practice ordered array of objects having a variety of colors (FIG. 1A; block 101). This practice ordered array 20 in FIG. 2A comprises a row 20 of colored squares 21, the colors here indicated by shading, as the drawing is in black and white. Preferably these objects 21 have a common shape, here, square, although this is not intended as a limitation. The subject is then prompted to practice by naming the object colors sequentially in order (block 102).

The practice phase second portion comprises the steps of displaying to the subject a practice ordered array of objects having a variety of shapes (block 103). This practice ordered array of objects in FIG. 2B comprises a row 22 of outlined shapes 24. Preferably these shapes have no color, although this is not intended as a limitation. The subject is prompted to practice by naming the object shapes sequentially in order (block 104).

The third portion of the practice phase of the test comprises the step of displaying a practice ordered array of objects having a variety of shapes and a variety of colors (block 105). In FIG. 3 the practice ordered array of objects having a variety of shapes and a variety of colors includes two rows 25 of four objects 26 each. The subject is prompted to practice by naming the shapes and colors sequentially in order in both rows (block 106).

In an alternate embodiment (FIG.1 E), during the practice phase, following one of the naming steps (blocks 102, 104, 106), if the subject makes more than a predetermined number of errors (block 139), the test administration is halted (block 140). If fewer than a predetermined errors is made (block 139), the test continues to the respective step (block 103, 105, 107, respectively). This occurs if the subject is apparently unable to complete the test satisfactorily.

In the main phase of the test administration method 100, three trials are administered to determine a level of adequacy in naming visual stimuli featured in the test: two single-dimension measures and one combination-naming task. The single-dimension tests are used to determine if motor-system dysfunction (e.g., dysarthria, apraxia), visual or perceptual deficits (e.g., color blindness, discrimination), or general slowness in responding causes a decrease in naming speed across the tasks. The speed and accuracy for single-dimension naming can be related directly to evidence from neuroimaging of regional cerebral blood flow to cortical activation of the occipital lobes.

Preferably the primary diagnostic measures are featured as the dual-dimension naming test of each task set. Continuous dual-dimension naming requires rapid and accurate perceptual and conceptual shifts between the dimensions and their associated semantic fields, known to occupy separate regions of the cortex. The scores obtained during color-form combination naming have been related directly to evidence of cortical activation of the parietal lobes associated with deactivation of the prefrontal lobes.

A first ordered array of objects having a variety of colors is displayed to the subject (block 107). Preferably the objects have a substantially analogous shape, here, squares, although this is not intended as a limitation. In FIG. 4 is illustrated an exemplary display of 40 squares 34 arrayed in a 5×8 matrix 35. As above, the squares 34 would preferably be colored, but are shown here with different shadings to represent colors. Preferably each object has a unitary shape, here, a square, although this is not intended as a limitation.

The subject is then prompted to name the object colors sequentially in order (block 108). The named object colors are then compared with the correct object colors (block 109). The examiner keeps a count of each incorrect answer, both self-corrected 71 and uncorrected 72, as well as the total number of errors 73 (block 110), and enters them on the Response Form 70 (FIG. 7; block 111) when all colors have been named on FIG. 4. Also, an interval taken by the subject to complete naming the object colors is timed, the interval 74 entered into the Response Form 70 (block 112).

The color-naming error count and interval are then compared with a predetermined color-naming error count and interval (block 113). An accuracy performance range 76 is indicated on the Response Form 70, as well as a time performance range 76, with blocks provided for ranges of normal, worse than normal, and non-normal performance. The maintained color-naming error count and/or the timed interval being greater than the predetermined color-naming error count and interval (block 114) is indicative of a possible parietal lobe function deficiency (block 115). If these criteria are satisfied (block 114), the subject passes this portion of the test (block 116).

In another portion of the method 100, a second ordered array of objects having a variety of shapes is displayed to the subject (block 117). An exemplary display for this portion of the test 100 is illustrated in FIG. 5, comprising a 5×8 matrix 36 of black shapes 37, although this is not intended as a limitation.

The subject is then prompted to name the object shapes sequentially in order (block 118). The named object shapes are compared with the correct object shapes by the examiner (block 119). The examiner keeps a count of each incorrect answer, both self-corrected 77 and uncorrected 78, as well as the total number of errors 79 (block 120), and enters them on the Response Form 70 (FIG. 7; block 121) when all shapes have been named on FIG. 5. Also, an interval taken by the subject to complete naming the object shapes is timed, the interval 80 entered into the Response Form 70 (block 122).

The shape-naming error count and interval are then compared with a predetermined shape-naming error count and interval (block 123). An accuracy performance range 81 is indicated on the Response Form 70, as well as a time performance range 82. The maintained shape-naming error count and/or the timed interval being greater than the predetermined shape-naming error count and interval (block 124) is indicative of a possible parietal lobe function deficiency (block 125). If these criteria are satisfied (block 124), the subject passes this portion of the test (block 126).

In yet a further portion of the method 100, a third ordered array of objects having a variety of shapes and a variety of colors is displayed to the subject (block 127). Such an exemplary array 38 is illustrated in FIG. 6, comprising a 5×8 matrix of objects 39.

The subject is then prompted to name the object colors and shapes sequentially in order (block 128). The named object colors and shapes are compared with the correct object colors and shapes by the examiner (block 129). The examiner keeps a count of each incorrect answer, both self-corrected 83 and uncorrected 84, as well as the total number of errors 85 (block 130), and enters them on the Response Form 70 (FIG. 7; block 131) when all colors and shapes have been named on FIG. 6. Also, an interval taken by the subject to complete naming the object colors and shapes is timed, the interval 86 entered into the Response Form 70 (block 132).

The color- and shape-naming error count and interval are then compared with a predetermined color- and shape-naming error count and interval (block 133). The maintained color- and shape-naming error count and/or the timed interval being greater than the predetermined shape-naming error count and interval (block 134) is indicative of a possible parietal lobe function deficiency (block 135). If these criteria are satisfied (block 134), the subject passes this portion of the test (block 136).

Preferably the method 100 is repeated (block 137), using, for example, a variety of other objects. A total of two color-object tasks are preferably given. Other exemplary objects may include, but are not intended to be limited to, letters 40 in a 5×8 array 41 (FIG. 10), numbers 42 in a 5×8 array 43 (FIG. 11), animals 44 in a 5×8 array 45 (FIG. 12), and household objects 46 in a 5×8 array 47 (FIG. 13).

In a preferred embodiment, the test is terminated after three presentations of color, shape, and color-shape arrays (block 138).

At least two of the task sets including color-form, color-number, and color-letter should preferably be given to obtain evidence of parietal lobe dysfunction. The color-animal and color-object tasks may be used as alternatives for the color-form task; these address working memory capacity and executive attention, which are believed to be important components of fluid reasoning and correlate with performances on higher-order cognitive tasks involving expressive language, word finding, reading comprehension, and complex learning and reasoning.

An exemplary chart 90 for placing the subject in a normality region is given in FIG. 7B, which comprises a two-dimensional comparison of subject data. In this graph two timed intervals form the ordinate and abscissa of the graph, and the subject is placed in a range of normal 91, slower than normal 92, or non-normal/pathological 93 based upon performance in two sectors of the test. It will be understood by one of skill in the art that any of the collected subject data can form such a two-dimensional representation, and that other data collected on the tests of the present invention may be used to form such a graph. Similarly, more than two dimensions may be used for such an evaluation, wherein n-dimensional modeling may be performed on a computer, for example. The three time performance ranges indicate:

1. Normal/typical.

2. Slower than normal, not clearly indicative of non-normal or pathological conditions such as dementia. The subject may be considered at risk and should be retested and/or referred for further neurological assessment.

3. Non-normal or pathological, suggests Alzheimer's disease or dementia. The subject should be referred for a CT scan, at minimum, to exclude any morphological changes or brain abnormalities before a diagnosis can be made.

The following exemplary tables provide ranges for naming times that are applicable for men and women between the ages of 15 and 75+ years: TABLE 1 Naming time (sec) criterion score ranges for combination-naming tests. Test Normal Slower than Normal Non-Normal Color-form <60 60-70 >70 Color-number <50 50-60 >60 Color-letter <50 50-60 >60 Color-animal <55 55-65 >65 Color-object <55 55-65 >65

TABLE 2 Naming time (sec) criterion score ranges for single-dimension naming tests. Test Normal Slower than Normal Non-Normal Color <25 25-35 >35 Form <30 30-40 >40 Number <20 20-30 >30 Letter <20 20-30 >30 Animal <35 35-40 >40 Object <35 35-40 >40

There are three accuracy performance ranges for men and women between the ages of 15 and 75+. When adolescents and adults do not meet the criteria for normal naming accuracy, there is generally evidence of neurological dysfunction associated with parietal lobe dysfunction such as in Alzheimer's disease, traumatic brain injury, Tourette syndrome, or ADHD. In those cases, the naming errors frequently reflect perseveration across adjacent stimuli. TABLE 3 Criterion Score Ranges for Naming Accuracy (Number of Errors) More Errors Than Test Normal Normal Non-Normal Color-form <2 3-4 >5 Color-number <2 3-4 >5 Color-letter <2 3-4 >5 Color-animal <2 3-4 >5 Color-object <2 3-4 >5

Response time and accuracy for each combination-naming test provide the basis for interpreting and describing a subject's test performance. The subject's naming time for each test should be compared with the criterion ranges to identify the range within which the performance lies. Subjects whose naming times lie in the slower-than-normal or non-normal range should be referred for further assessment and/or CT scan to rule out morphological changes or brain abnormalities.

Any combination-naming accuracy score out of the normal range in each task set should be compared with the naming time performance range for that test. In some cases, naming time may be within the normal range, while naming accuracy is out of the normal range. This may occur with ADHD, lack of inhibition (impulsivity), organic brain injury, or aphasia. In these cases, testing should be repeated after a short rest period. If the subject's naming accuracy is still out of the normal range, an assessment for specific word-finding difficulties (dysnomia) should be administered). When naming accuracy measures are in the non-normal range, the errors are often perseveration, substitutions, or omissions and may require further exploration.

If the single-dimension naming times are within the normal range, but the dual-dimension naming times lie outside the normal range, the results match the performance pattern of adults with verified parietal lobe dysfunction.

If the times for the primary combination-naming tests (color-form, color-number, color-letter) lie within the normal range, the subject passes screening, with no evidence of parietal lobe dysfunction.

Naming times that are in the slower-than-normal range for two of the primary combination-naming tests (color-form and color-number or color-form and color-letter) indicate a slowing of processing speed, which can be seen in developmental disorders (e.g., ADHD, dyslexia, specific language impairments, or Tourefte syndrome) or in neurogenic disorders (e.g., TBI or ischemic CVA).

Naming times in the non-normal range for the primary screening tasks indicate:

-   -   1. Clinically significant deficits in processing speed, working         memory, automaticity and fluency of retrieval and production,         and executive memory     -   2. Deterioration of parietal-lobe functions (e.g., Alzheimer's         disease)     -   3. Pervasive cognitive impairments involving other brain         structures (e.g., global dementia)     -   4. The presence of structural brain abnormalities

In these cases a CT scan is necessary to rule out brain abnormalities (e.g., tumor, CVA, or TBI) that may cause similar naming-speed deficits. In all cases in which Alzheimer's disease is suspected because combination-naming times are in the non-normal range, the subject should be referred for a follow-up evaluation to rule out morphological changes or brain abnormalities.

A deficit in naming speed, especially in adolescents and young adults, may also indicate a developmental language disorder associated with reduced word retrieval and expressive language problems or an acquired language disorder after TBI. In everyday contexts, these deficits are often characterized by word-finding difficulties (dysnomia/anomia), non-fluency (e.g., slow rate of speech, high number of pauses, hesitations, revisions, self-corrections, and circumlocutions, and by disorganization in complex language production. In that case, an in-depth language assessment is indicated.

Naming speed deficits may be indicators of dyslexia. Deficits in naming speed for color-letter combinations, in the presence of normal speed for naming color-form, color-number, color-animal, and/or color-object combinations may reflect a neurolinguistic deficit related to reading difficulties (dyslexia). A color-letter naming speed deficit can occur in isolation, while other combination-naming times are within normal limits in adolescents and adults with dyslexia. A subject with this pattern should be referred for follow-up evaluation for dysnomia and reading disability.

Naming times for the single-dimension stimuli provide a baseline for interpreting the results of each combination-naming task. Preferably three tests are administered, and performance may then be interpreted as follows:

1. If the naming times for three combination-naming tests lie within the non-normal range, there is compelling evidence of parietal lobe dysfunction, and the subject should be referred for follow-up evaluation (e.g., CT scan).

2. If only two tests were administered owing to subject fatigue or another reason, and the naming times for two consecutive combination-naming tests lie in the non-normal range, there is compelling evidence of parietal lobe dysfunction, and a follow-up evaluation should be considered (e.g., CT scan).

3. If the naming times for the primary combination-naming tasks are in the normal range, there is no evidence of parietal lobe dysfunction, and reasons why the subject was referred may be explored.

4. If the naming times for two of the three combination-naming tasks lie within the normal range and one lies outside the normal range, repeat the screening if the performance may reflect anxiety or other emotional reactions. If the performance is consistent, the presence of, for example, ADHD, epilepsy, language impairment, or learning disability may be suggested.

5. If the total naming times for two of the three primary combination-naming tests lie within the non-normal range, examine the content of the tests that were performed within the non-normal range. It appears that the color-form combination-naming time is most sensitive to the early effects of Alzheimer's disease. As the disease progresses, the naming times for the color-number and color-letter combination tests appear to increase, until all performances are within the non-normal range. The observation of such a pattern warrants a referral for follow-up.

In an alternate embodiment of the invention, the parietal lobe function test is delivered and analyzed by a software-driven computerized system 50, a schematic diagram for which is given in FIG. 8. The system 50 comprises a processor 51 in signal communication with a timing device 52, a display device such as a color video monitor 53, and an input device such as a keyboard 54 and/or a pointing device such as a mouse 55. Alternatively, the display and input devices may comprise a unitary device such as a touch screen. One of skill in the art will appreciate that the scope of the invention is not intended to be limited to a particular hardware configuration.

A database 56 is accessible by the processor 51 that contains a set of predetermined standard data against which the current subject's test data may be compared. Such data may include, for example, age-sorted data, or such data arranged or sortable in other desired categories.

A software package 57 is installable on the processor 51 that is adapted to mediate the displaying functions as outlined above for displaying screens analogous to FIGS. 2A-6. The software package 57 is also adapted to receive from an examiner via one of the input devices 54,55 a count of errors in the named object colors, shapes, and color-shapes and to time an interval taken by the subject to complete the naming process by accessing the timing device 52. The software package 57 also accesses the database 56 for a set of predetermined error count and interval data and automatically makes comparisons of the error counts and intervals with the predetermined error count and interval data for determining a possible parietal lobe function deficiency as above.

Following the comparisons, the results are output to the examiner.

In yet a further embodiment of the system 60, a schematic for which is shown in FIG. 9A, the test portions may be administered in totally automated fashion, without an examiner, mediated by a software package 61 resident on a processor 62. In this embodiment 60 the software package 61 performs all the displaying, receiving, and analysis functions by interacting directly with the subject, and hence the “examiner” in FIGS. 1A-1D comprises the software package 61 itself. The displays are made on monitor 63, and the subject inputs named objects, shapes, and color-shapes via an input device such as a pointing device 64, keyboard 65, or, most preferably, a microphone 68 in signal communication with the processor 62, in communication with voice-recognition software 69 for interpreting the subject's oral answers. Alternatively, the monitor 63 may comprise a touch screen, serving as input and output device.

In this embodiment 60 the displays include not only the objects to be named for color and/or shape, but also selections, such as a list of colors and shapes to be selected by the subject using the input device. The software package 61 then mediates the timing 66, database 67 access, and analysis functions automatically.

In a subembodiment, the software package 61 comprises a set of rules for determining how and whether to continue the test administration steps based upon performance criteria. For example, if the subject performs below a predetermined minimum level on at least one portion of the practice phase, or on at least one of the trials in the main phase of the test administration, the administration can be halted or re-routed.

A system 60′ analogous to the automated embodiment 60 may also be implemented remotely, such as over an intranet or the Internet 70 (FIG. 9B). In this case 60′, the software package 61′ is resident on a remote processor 62′, in communication with database 67′, at a remote site 72. The software package 61′ is accessible over a communication means, for example, a modem 71 to, for example, a web site. The subject's processor 62″, located at the subject site 73, then interfaces with the software package 61′ and mediates the subject interactions via local hardware and software. The invention is not intended to be limited to a particular hardware configuration, and one of skill in the art will recognize alternate equivalent configurations for performing the interaction.

An additional benefit of a remote embodiment 60′ is that the results of each administration could be captured as data for subsequent manipulation to update normative data and for research purposes. For example, blind studies could be studied with such amassed data using demographic subject information.

It may be appreciated by one skilled in the art that additional embodiments may be contemplated, including alternate forms of display and of object configurations, and alternate data manipulation and collection methods.

In the foregoing description, certain terms have been used for brevity, clarity, and understanding, but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such words are used for description purposes herein and are intended to be broadly construed. Moreover, the embodiments of the apparatus illustrated and described herein are by way of example, and the scope of the invention is not limited to the exact details of construction.

Having now described the invention, the construction, the operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby, the new and useful constructions, and reasonable mechanical equivalents thereof obvious to those skilled in the art, are set forth in the appended claims. 

1. A method for testing occipital lobe function in a subject, the method comprising the steps of: displaying to a subject a first ordered array of objects having a variety of colors, each object having a unitary color; prompting the subject to name the object colors sequentially in order; comparing the named object colors with the correct object colors; maintaining a count of errors in the named object colors; timing an interval taken by the subject to complete naming the object colors; comparing the color-naming error count and interval with a predetermined color-naming error count and interval, a color-naming error count and interval greater than the predetermined color-naming error count and interval indicative of a possible parietal lobe function deficiency; displaying to the subject a second ordered array of objects having a variety of shapes; prompting the subject to name the object shapes sequentially in order; comparing the named object shapes with the correct object shapes; maintaining a count of errors in the named object shapes; timing an interval taken by the subject to complete naming the object shapes; and comparing the shape-naming error count and interval with a predetermined shape-naming error count and interval, a shape-naming error count and interval greater than the predetermined shape-naming error count and interval indicative of a possible occipital lobe function deficiency.
 2. The method recited in claim 1, wherein the objects in the first ordered array all have a substantially analogous shape.
 3. The testing system recited in claim 1, wherein the objects in the second ordered array all have a-substantially analogous color.
 4. A method for testing parietal lobe function in a subject, the method comprising the steps of: displaying to the subject a first ordered array of objects having two features, a first feature and a second feature within a first and a second unitary dimension, respectively, the first dimension different from the second dimension; prompting the subject to name the first and the second feature of each first-array object sequentially in order; comparing the named first-array object first and second feature with a correct first-array object first and second feature, respectively; maintaining a first count of errors in the named first and second features; timing a first interval taken by the subject to complete naming the first and second features; comparing the first error count and interval with a predetermined first error count and interval, a first error count and interval greater than the predetermined first error count and interval indicative of a possible parietal lobe function deficiency; displaying to the subject a second ordered array of objects having two features, a third feature and a fourth feature within a third and a fourth unitary dimension, respectively, the third dimension different from the fourth dimension; prompting the subject to name the third and the fourth feature of each second-array object sequentially in order; comparing the named second-array object third and fourth feature with a correct second-array object third and fourth feature, respectively; maintaining a second count of errors in the named third and fourth features; timing a second interval taken by the subject to complete naming the third and fourth features; comparing the second error count and interval with a predetermined second error count and interval, a second error count and interval greater than the predetermined second error count and interval indicative of a possible parietal lobe function deficiency.
 5. The method recited in claim 4, further comprising the step of performing a two-dimensional comparison of subject data for determining a possible parietal lobe deficiency, the subject data comprising at least one of the first feature and second feature naming error count for the first ordered array versus the third feature and the fourth feature naming error count for the second ordered array and the first and the second feature naming interval for the first ordered array versus the third and the fourth feature naming interval for the second ordered array.
 6. A method for testing parietal lobe function in a subject, the method comprising the steps of: displaying to a subject a first ordered array of objects, each first-array object having a feature within a first unitary dimension; prompting the subject to name the feature of each first-array object sequentially in order; comparing the named first-array object features with respective correct first-array object features; maintaining a first count of errors in the named first-array object features; timing a first interval taken by the subject to complete naming the first-array object features; comparing the first error count and interval with a predetermined first error count and interval; displaying to the subject a second ordered array of objects, each second-array object having a second and a third feature within a second and a third unitary dimension, the second dimension distinct from the third unitary dimension; prompting the subject to name the second and third feature of each second-array object sequentially in order; comparing the named second-array object second and third features with correct second-array object second and third features; maintaining a second count of errors in the named second-array object second and third features; timing a second interval taken by the subject to complete naming the second-array object second and third features; comparing the second error count and interval with a predetermined second error count and interval; wherein a first error count and interval equal to or less than a predetermined first error count and interval, combined with a second error count and interval greater than the predetermined second error count and interval, indicative of a possible parietal lobe function deficiency.
 7. A method for testing for a developmental language disorder in a subject, the method comprising the steps of: displaying to the subject a first ordered array of objects having two features, a first feature and a second feature within a first and a second unitary dimension, respectively, the first dimension different from the second dimension; prompting the subject to name the first and the second feature of each first-array object sequentially in order; timing a first interval taken by the subject to complete naming the first and second features; comparing the first interval with a predetermined first interval; displaying to the subject a second ordered array of objects having two features, a third feature and a fourth feature within a third and a fourth unitary dimension, respectively, the third dimension different from the fourth dimension; prompting the subject to name the third and the fourth feature of each second-array object sequentially in order; timing a second interval taken by the subject to complete naming the third and fourth features; comparing the second interval with a predetermined second interval, a second interval greater than the predetermined second interval, combined with a first interval greater than the predetermined first interval, indicative of a possible developmental language disorder. 